Renysmom, I had the same problem last night when choosing Coronado. I think the website is set up improperly or that for our dates of 8/28 - 9/2 Coronado wasn't available... I tried it three different times and then realized there was nothing I could do. Very frustraing!
After booking at POR and setting up my itenirary I continued to have problems... Called Disney they said their system was down today!